Ariane 5 explosion during its maiden flight in 1996

On June 4th, 1996, Ariane 5 exploded at an altitude of 4000 meters (13 000 feet), while it was performing its first flight.
The cause of the failure is the total loss of guidance and altitude data 37 seconds after the ignition sequence of the main engine (30 seconds after lift-off). This loss of data is due to errors during the specification and design of the inertial reference system.
Nozzles received the order of an important correction of the trajectory. Therefore, the rocket turned violently and disintegrated because of the high aerodynamic loads. Self destruction has been activated immediately after the beginning of the disintegration.